Existing recently-developed NMR technology will be assessed for its applicability in realistic contexts, and new NMR methods will be developed. It is intended to pursue liquid-state and solid-state NMR with equal emphasis, to promote cross-fertilization of ideas between these traditionally separate disciplines. Multiple-quantum filtration methods will be developed leading to simplification of 2D spectra and selective NMR on subsystems of chosen coupling networks in medium-sized biomolecules. A long-term aim is to develop NMR methods allowing (for example) selective detection of a particular set of amino acid residues (e.g. alanines) in a small protein. 2D Methods for monitoring the complete set of transition probabilities: Generalized NOE spectroscopy will be introduced for study of relaxation and chemical exchange in multi-level systems. The expectation is that more detailed definition of the relaxation properties, including multiple-spin relaxation processes, will allow more information to be extracted than from simple spin-lattice relaxation time constants or cross-relaxation time constants (NOE's). Composite pulse techniques for quadrupolar spins in solids: The effect of molecular motion on lineshapes produced by the new composite pulse excitation techniques will be investigated. Improved composite pulses will be developed for spin excitation, inversion and other manipulations in both spin-1 and spin-1/2 systems. Development of broadband cycles and other composite pulses: New broadband cycles will be developed for applications to heteronuclear decoupling, isotropic mixing, and for conversion into other composite pulses with a wide spectrum of applications in high resolution NMR. Development of continuous modulation schemes: Irradiation strategies employing continuously-varying phase amplitude will be employed for selective spin excitation, inversion and solvent suppression. Development of polarization transfer techniques: New modulated pulse schemes will lead to efficient transfer of polarization between different spin species in liquids and solids.
|McDermott, A E; Creuzet, F; Gebhard, R et al. (1994) Determination of internuclear distances and the orientation of functional groups by solid-state NMR: rotational resonance study of the conformation of retinal in bacteriorhodopsin. Biochemistry 33:6129-36|
|Levitt, M H; Kolbert, A C; Bielecki, A et al. (1993) High-resolution 1H NMR in solids with frequency-switched multiple-pulse sequences. Solid State Nucl Magn Reson 2:151-63|
|Creuzet, F; McDermott, A; Gebhard, R et al. (1991) Determination of membrane protein structure by rotational resonance NMR: bacteriorhodopsin. Science 251:783-6|